The best type of business relationships are the ones where each party only benefits. No downsides. This sounds obvious but it's worth acknowledging because I realize how rare they actually are.
In my experience, even the best opportunities involve at least a little bit of opportunity cost: the chance that you might be missing out on something better by seizing the opportunity. While deals may not be perfect, sometimes it's still worth taking.
I'm currently in a situation where an opportunity is so good there doesn't seem to be any downsides. The best part? I bet the other party would say the same thing.
Absolute mutualism. It's like two puzzle pieces fitting together perfectly, and damn it feels good.